By Karolos Grohmann
(Reuters) - Leaders Bayern Munich are racing to get key players fit in time for Saturday's big Bundesliga clash against Borussia Dortmund, with Thomas Mueller, Douglas Costa and keeper Manuel Neuer still in doubt.
Winger Costa returned to team training on Wednesday, a day after their 1-0 loss to Hoffenheim - only Bayern's second league defeat of the season - but completed only parts of it as he works towards his comeback from a mid-March knee injury.
With Mueller and Neuer training alone, things seemed to take a turn for the worse on Thursday when Lewandowski, who has netted 24 times in the league, had to break off training, clutching his thigh.
But the Pole will play against his former club, saying on Twitter: "Everything is fine. I will be ready."
Despite their midweek defeat, Bayern, chasing a record-extending fifth consecutive league title, still command a comfortable 10-point advantage over second-placed RB Leipzig.
But with Real Madrid awaiting in the Champions League quarter-final next week, Bayern know too well a slip-up against Dortmund could seriously dent their self-confidence.
"That was a setback at just the right time," defender Mats Hummels said of their first ever loss to Hoffenheim. "It is obvious that when we are passive in our game we are not even half as strong as when we bring a certain intensity into it.
"So on Saturday we will give it all we have," said Hummels.
Dortmund, champions in 2011 and 2012 before Bayern's domination, wrote off their own title chances early in the campaign and are now desperately trying not to miss out on Champions League action next season.
The Ruhr valley club, who face AS Monaco in the Champions League last eight, are in fourth place, a point behind Hoffenheim.
They will now need to replicate Hoffenheim's result against the champions if they are to stay within striking distance of Hoffenheim with six matches left in the season after Saturday.
The top three teams win an automatic Champions League group stage spot while the fourth team must go through a qualifying round.
Despite possessing the league's best scorer in Pierre-Emerick Aubameyang, who has 25 goals, Dortmund coach Thomas Tuchel has seen his team waste a myriad of chances throughout the season, dropping points they now urgently need to grab back.
"You can see in our game the number of wasted goal chances, one after the other, the many games where we have failed to knock out the opponent," Tuchel said, following their midweek 3-0 win over Hamburg SV.
(Reporting by Karolos Grohmann; editing by Mark Heinrich)